1. Brouwers, H. B., Biffi, A., McNamara, K. A., Ayres, A. M., Valant, V., Schwab, K., Romero, J. M., et al. (2012). Apolipoprotein E Genotype Is Associated With CT Angiography Spot Sign in Lobar Intracerebral Hemorrhage. Stroke, 43(8), 2120–5. doi:10.1161/STROKEAHA.112.659094
Extravasation of contrast into a parenchymal hematoma on CTA is termed the “spot sign.” This sign is frequently seen in patients with ICH and is an independent predictor of both hematoma expansion and poor outcome. The authors looked at the relationship of the spot sign to patient’s genetics, with either the ε2 or ε4 allele (apolipoprotein E, i.e., APOE), which are associated with an increased risk of lobar hemorrhage.
They found that the APOE ε2 allele is associated with the presence of the CTA spot sign in patients with lobar ICH. Patients on warfarin are also more likely to have a spot sign upon presentation regardless of ICH location. Given the known relationship between APOE ε2 and vasculopathic changes in amyloid angiopathy, their findings suggest that both hemostatic factors and vessel pathology influence the development of the spot sign and risk of prolonged bleeding in ICH.
2. Ceccarelli, A., Bakshi, R., & Neema, M. (2012). MRI in multiple sclerosis: a review of the current literature. Current Opinion in Neurology, 25(4), 402–9. doi:10.1097/WCO.0b013e328354f63f
Nice summary of the most important papers regarding imaging of MS from late 2010 to early 2012. UHF 7T MRI has the potential to differentiate between MS and non-MS white matter lesions based on morphology, with the presence of a central vein in white matter lesions being a distinguishing feature. Double-inversion recovery imaging and dynamic contrast-enhanced imaging has improved the visualization and characterization of damage in white matter and gray matter. 54 references and 4 figures.
3. Dirks, M. S., Butman, J. a, Kim, H. J., Wu, T., Morgan, K., Tran, A. P., Lonser, R. R., et al. (2012). Long-term natural history of neurofibromatosis Type 2-associated intracranial tumors. Journal of Neurosurgery, 117(1), 109–17. doi:10.3171/2012.3.JNS111649
17 patients with NF2 were followed for a mean of 9.5 years. In the 1990s, the median life expectancy after diagnosis was 15 years, with virtually all NF2 patients progressing to bilateral deafness. As the authors note, despite significant advances in diagnosis, surveillance, genetic testing and improved microsurgical, rehabilitative, and radiation therapy techniques, the majority of patients in this study had bilateral hearing loss and were rendered unable to work as a result of an NF2-associated disability (KPS score ≤ 70 in 7 patients).
4. Dunn, G. P., Fecci, P. E., & Curry, W. T. (2012). Cancer Immunoediting in Malignant Glioma. Neurosurgery, 71(2), 201-222. doi:10.1227/NEU.0b013e31824f840d
Worthwhile effort to read this, even though I understood about 10%. Actually, the language is very approachable until about page 208 where I got bogged down in the details. Even a superficial skimming will give you a sense of the tremendous potential in this area. 315 references!
5. Dusek, P., & Schneider, S. a. (2012). Neurodegeneration with brain iron accumulation. Current Opinion in Neurology, 25(4), 499–506. doi:10.1097/WCO.0b013e3283550cac
Neurodegeneration with brain iron accumulation (NBIA) disorders are a highly heterogenous group of diseases caused by mutation in the genes involved in a wide variety of iron metabolic pathways, phospholipid metabolism or lysosomal function. This review covers all the main players (and many obscure diagnoses) in a succinct fashion. Table 1 is particularly useful as a listing of the disorders sorted by likely age of onset. 46 references.
6. Gross, B. a, & Du, R. (2012). Hemorrhage from arteriovenous malformations during pregnancy. Neurosurgery, 71(2), 349–56. doi:10.1227/NEU.0b013e318256c34b
The authors reviewed the records of 54 women with an angiographic diagnosis of an AVM. Annual hemorrhage rates were calculated as the ratio of the number of bleeds to total number of patient-years of follow-up. The annual hemorrhage rate for an AVM when not pregnant was 1.1%. The annual hemorrhage rate when pregnant was 10.8%. 4 cases studies included, and 6 figures.
7. Jickling, G. C., Stamova, B., Ander, B. P., Zhan, X., Liu, D., Sison, S.-M., Verro, P., et al. (2012). Prediction of Cardioembolic, Arterial, and Lacunar Causes of Cryptogenic Stroke by Gene Expression and Infarct Location. Stroke, 43(8), 2036–2041. doi:10.1161/STROKEAHA.111.648725
The authors describe the integration of 2 gene expression profiles with a measure of infarct location on neuroimaging to predict the probable cause of cryptogenic stroke The strokes were classified as either lacunar, arterial, cardioembolic or unknown. Lacunar stroke was only a consideration when the infarct was located in the region of the penetrating arteries, hence the neuroimaging correlation. The genetic profiles are based on differential inflammatory and prothrombotic states present in subtypes of stroke. They show that RNA expression profiles (from a peripheral blood draw) can predict a likely cause in cryptogenic stroke.
8. McFadden, J. T. (2012). Magnetic resonance imaging and aneurysm clips. Journal of Neurosurgery, 117(1), 1–11. doi:10.3171/2012.1.JNS111786
Extensive review, with much historical data, and an overly authoritative tone. I offer two quotes:
“The neurosurgeon clipping an aneurysm today has no need for anything written by a radiologist about clips…”
“No metal offenders remain in the picture; stainless steel is gone, and everything of the canon is nonferromagnetic when exposed to current scanners. To have to test each clip before use for a property known to be absent is absurd.”
See page 8 for some useful guidelines.
9. Sanai, N., Caldwell, N., Englot, D. J., & Lawton, M. T. (2012). Advanced technical skills are required for microsurgical clipping of posterior communicating artery aneurysms in the endovascular era. Neurosurgery, 71(2), 285–95. doi:10.1227/NEU.0b013e318256c3eb
Endovascular therapy has removed from surgical approach the simple aneurysms that would have been easiest to clip. What remains are aneurysms with complex anatomy and worst outcomes. The current mix of posterior communicating artery aneurysms requires advanced techniques including clinoidectomy, anterior choroidal artery microdissection, complex clipping, and facility with intraoperative rupture.
10. Tao, W.-D., Liu, M., Fisher, M., Wang, D.-R., Li, J., Furie, K. L., Hao, Z.-L., et al. (2012). Posterior versus anterior circulation infarction: how different are the neurological deficits? Stroke, 43(8), 2060–5. doi:10.1161/STROKEAHA.112.652420
Finally, something that gives me some job security: The authors found that there was no apparent difference in the frequency of the most common symptoms/signs between posterior circulation infarcts and anterior circulation infarcts. Some neurological deficits were highly specific for diagnosing PCI, but their sensitivity suggests that symptoms or signs considered typical of PCI are uncommon. Inaccurate localization would be common if clinicians only relied on clinical symptoms and signs to differentiate anterior from posterior infarcts.
11. Xiao, B., Wu, F.-F., Zhang, H., & Ma, Y.-B. (2012). A randomized study of urgent computed tomography-based hematoma puncture and aspiration in the emergency department and subsequent evacuation using craniectomy versus craniectomy only. Journal of Neurosurgery, 117(3), 566-73. doi:10.3171/2012.5.JNS111611
Interesting study treating patients with very large intraparenchymal hematomas with urgent CT based puncture and aspiration in the ED, followed by more conventional OR based evacuation. 36 patients with >70cc hemorrhages were divided into two groups: “A” underwent ED based aspiration and subsequent craniotomy and “B” had hematoma evacuation with craniotomy only. The volume of aspirated blood in group A ranged from 21 to 35 ml (mean 26.6 ± 3.8 ml). Group A had a higher survival rate than B at 12 months after surgery (p < 0.05), and Barthel Scale scores in Group A survivors were better than those in Group B survivors (p < 0.05). Repeat CT scanning was not performed in group A, and the catheter was removed in the OR at the time of craniotomy, so the exact position of the catheters is unknown.
12. Gross, B. a, & Du, R. (2012). The natural history of cerebral dural arteriovenous fistulae. Neurosurgery, 71(3), 594–603. doi:10.1227/NEU.0b013e31825eabdb
It would seem that the presence or absence of leptomeningeal venous drainage alone (Borden type II or III) increases hemorrhagic risk and is likely the only truly consistent and relevant factor for determining that risk.
13. Riedel, C. H., Zoubie, J., Ulmer, S., Gierthmuehlen, J., & Jansen, O. (2012). Thin-Slice Reconstructions of Nonenhanced CT Images Allow for Detection of Thrombus in Acute Stroke. Stroke, 43, 2319–2323. doi:10.1161/STROKEAHA.112.649921
Three observers independently evaluated the 5-mm nonenhanced CT reconstructions and 5-mm maximum intensity projections of the thin slices and rated the likelihood of a clot obliterating the middle cerebral artery trunk or first-order branches using a 5-point scale in 54 patients presenting with acute ischemic stroke. The CT images wee reconstructed with a slice thickness of 0.625 mm and subsequently converted into 5-mm thick slices using maximum intensity projections (MIPs) without a reconstruction increment. The thin-slice reconstructions of standard cranial nonenhanced CT raw data allow for more sensitive and reliable detection of clots in the MCA. [We use this technique routinely for acute stroke evaluation. The hyperdense MCA sign is much easier to visualize on the MIP thin slice reconstructions.]
